DE102010056148A1 - filter - Google Patents

Abstract

A filter for filtering media having a pleated cylindrical filter element disposed between a perforated cylindrical backflow preventer and a perforated cylindrical core, the filter element being arranged in pleated folds, wherein a plurality of pleats has a first pleat height that is greater as the difference between the radius of the backflow preventer and the radius of the core and that directed away from the outer surface of the core are each tilted at a pitch angle from a radial, wherein a plurality of pleats are provided at least a second shorter pleat height and wherein the pleats of the second shorter fold height of the backflow protection radially outwardly adjacent to the folds of the first fold height adjacent to the change are arranged.

Description

Field of the invention

The invention relates to a filter for filtering media with a pleated, cylindrical filter element, which is arranged between a perforated cylindrical backflow preventer and a perforated cylindrical core, wherein the filter element is arranged in pleated folds, wherein a plurality of folds has a first pleat height is greater than the difference between the radius of the backwater and the radius of the core and which are directed away from the outer surface of the core away from a radial inclined by an inclination angle.

State of the art

Optimized pleats or fold geometries are used to circumvent the classical problem of the star-shaped pleat fold arrangement in the cylindrical filter element. This folding arrangement uses radial folds of the same fold height, which are tightly pressed on the tightest circumference of the core, but far apart from the outer circumference on the backflow preventer. In this way, a large proportion of the existing space can not be filled with filter material and the mechanical stability in the outer region of the filter element is limited by the possibility of movement of the folds in the intervening spaces. Reached filter surfaces with two membrane layers are about 0.5 to 0.7 square meters per 10 inch element.

An increase in the filter area is often achieved with the help of thinner filter or especially thin drainage or spacer materials. The number of folds per filter element and thus the filter area increases. A disadvantageous consequence is a reduced mechanical stability of the folds of these thinner materials. In addition, the flow of filter material between the pleats is associated with increasing flow resistance when using thinner drainage materials. Therefore, the flow rate can decrease despite increased filter surface. In addition, there is a risk that the end areas of the spaces between the folds can no longer be flown or form air pockets. The filter area in these areas is then inactive.

The basic aim is to increase the filtration performance as a function of flow and service life.

From the DE 693 29 118 T2 , of the DE 693 34 045 T2 and from the DE 693 33 430 T2 , belonging to the same patent family, a filter is known which comprises a pleated, cylindrical filter element which is arranged between a backflow preventer and a core. The filter element is formed in multiple layers and arranged in pleated folds having a pleat height which is greater than the difference between the radius of the outer cylinder and the radius of the core. The folds are directed away from the outer surface of the core in the tangential direction arcuate and each have a tilt angle relative to a radial.

In this case, the fold height can be increased significantly, these overlong folds being inclined towards the outer cylinder more and more tangentially, so that even space not previously filled with filter material can be filled out to the outer cylinder.

A disadvantage of this known filter, however, are the long to be flowed through wrinkles interstices. There is a risk that the end areas of the spaces between the folds can no longer be flown or form air pockets. The filter area in these areas is then inactive.

Furthermore, from the DE 39 35 503 C2 a ring filter element of a zigzag-shaped folded filter material with radially aligned, over the radial depth of different lengths wrinkles, of which the shorter are radially outward known. Each should be followed by a short at least two long wrinkles, each having the short and the long wrinkles over the entire circumference, each having an equal radial depth.

A disadvantage of these radially arranged long folds and the short folds between them is that the available filter area is relatively small, which leads to an insufficient filtration performance. Furthermore, with such filters, the stability needs improvement.

task

Object of the present invention is to improve the known filter so that their performance and in particular their service life, are increased at the same time good mechanical stability of the filter element.

Presentation of the invention

This object is achieved in conjunction with the preamble of claim 1, characterized in that a plurality of wrinkles at least a second shorter fold height is provided and that the folds of the second shorter fold height of the backflow preventer radially adjacent and alternately the folds of the first fold height are arranged adjacent.

The shorter wrinkles fill the larger circumference radially outward. At the core, the available circumference decreases, therefore, the longer wrinkles remain inward or end at the core, while the shorter wrinkles, seen from the outside, terminate between the core and backflow protection. The inwardly remaining long pleats, which are inclined relative to a radial by an inclination angle, have a high mechanical load capacity, which continues in the region of the outer periphery for backflow protection through the interposed folds of a second shorter pleat height. Surprisingly, the performance in terms of service life increases sharply. Because of its high mechanical stability and its increased service life with good flow performance of the filter according to the invention is also well suited for industrial applications with pressure fluctuations or pressure surges as well as thermal stresses in superheated steam sterilization.

According to a preferred embodiment of the invention, the number of pleats having a shorter pleat height is half the number of pleats having the first higher pleat height. This means a 2: 1 fold ratio of the pleats having the first longer pleat height to the pleats having the second shorter pleat height.

According to a further preferred embodiment of the invention, the number of folds with a shorter fold height corresponds to the number of folds with the first fold height. Thus, the ratio of the wrinkles with the first longer pleat height and the pleats with the second shorter pleat height is 1: 1.

According to another preferred embodiment of the invention, the folds of the shorter, second pleat height end at their backstop averted end approximately on a virtual radius that is greater than or equal to the radius of the core increased by one quarter of the difference between the radius of the backpressure protection and the radius of the core. A virtual radius, which is about the same as the radius of the core increased by half the difference between the radius of the backflow protection and the radius of the core, has proven to be favorable

The folds of the first fold height each have an inclination angle of greater than 15 °, at least in their region not adjacent to folding of a second fold height, that is to say in a region lying within the virtual radius.

For example, with a fold ratio of 2: 1, an inclination angle of 20 ° in the near region of the inner cylinder has proved favorable.

According to a further preferred embodiment of the invention, the folds of the first fold height each have an angle of inclination greater than 25 °. More preferably, the folds of the first fold height each have an angle of inclination of greater than 40 °.

Thus, for example, with a fold ratio of 1: 1, an angle of inclination of 50 ° with respect to the water flow has proven favorable.

In a further embodiment, an angle of inclination of 60 °, in particular for the service life, has proved to be favorable given a fold ratio of 1: 1.

According to a further preferred embodiment of the invention, the filter element consists of successively arranged, one or more layers of drainage or spacer material, one or more layers of filter material with a selective separation ability when flowing through and finally again one or more layers of drainage or spacer material.

The filter material may be formed of a polymeric porous membrane of polyethersulfone (PESU) or polyamide or polyvinylidene fluoride or a cellulose derivative, such as cellulose mixed ester, cellulose acetate, cellulose nitrate or cellulose or polypropylene or polyethylene or polytetrafluoroethylene and / or expanded polytetrafluoroethylene or polyvinyl chloride.

The filter material can also be formed from mineral or polymeric fiber filter media or bonded and / or unbonded nonwovens, such as spunbonded or melt blown spunbonded nonwoven or stapled nonwoven or carded nonwovens, or cellulose or polyester or polyolefins, such as PE or PP, or glass fibers or microglass fibers. Finally, it is possible that the filter material is formed of a woven or extruded net of a polymer as above.

Further, it is possible that the filter material is formed of a functionalized porous filter medium, such as a modified polymer membrane of polyamide or polyethersulfone or cellulose acetate.

Further details of the invention will become apparent from the following detailed description and the accompanying drawings, in which preferred embodiments of the invention are illustrated by way of example.

Brief description of the drawings

In the drawings show:

1 FIG. 2 is a plan view, on an enlarged scale and in elevation, of a first embodiment of a filter. FIG.

2 FIG. 2 is a plan view in enlarged scale and in elevation of a second embodiment of a filter. FIG.

3 FIG. 2 is a plan view, in enlarged scale and in elevation, of a third embodiment of a filter. FIG.

4 FIG. 2 is a plan view, on an enlarged scale and in elevation, of a comparative filter according to the prior art. FIG.

5 FIG. 4 is an enlarged plan view of the embodiment of the filter of FIG 1 with partly shown filter element,

6 FIG. 4 is an enlarged plan view of the embodiment of the filter of FIG 2 with partially shown filter element and

7 FIG. 4 is an enlarged plan view of the embodiment of the filter of FIG 3 with partly shown filter element.

Description of the embodiments

A filter 1 consists essentially of a filter element 2 , a backwater protection 3 and a core 4 ,

The filter element 2 is multi-layered and in pleated first folds 5 a first fold height 6 and second wrinkles 7 a second fold height 8th arranged.

The first fold height 6 the first wrinkles 5 is greater than the difference between the radius (inner radius) 9 the backwater protection 3 (eg an outer cylinder) and the radius (outer radius) 10 of the core 4 (For example, an inner cylinder).

The first wrinkles 5 the first fold height 6 do not point in their second folds 7 the second fold height 8th adjacent area of the outer surface 11 of the core 4 directed away, each opposite a radial 12 a tilt angle 13 on.

The second folds 7 with the shorter second fold height 8th end up at their backwater barrier 3 opposite end 14 about on a virtual radius 15 that is greater than or equal to the radius 10 of the core 4 increased by half the difference between the radius 9 the backwater protection 3 and the radius 10 of the core 4 , This corresponds to the virtual radius 15 at least half the sum of the two radii 9 . 10 ,

With four different filter elements 2 , according to the embodiments of 1 to 3 and two comparative filter elements according to the prior art according to 4 In each case the filtration performance was measured as a function of the service life and the water flow.

Description of the measurement life:

The measurement of the service life is carried out with a liquid aqueous solution which is capable of blocking microfiltration filter elements with a controllable volume in the laboratory.

The model solution consists of a dilute, aqueous solution of KSE coffee surrogate extract, Art. No. 061114, Günzburger food factory Gebr. Strehle GmbH, Auweg 1, 89312 Günzburg, and Ovomaltine NF 500 g, Art. No. 2300028, Importer Wilms , Heinrich-Hertz-Straße 2, 65232 Taunusstein.

The measurement is carried out by feeding the solution into a filter housing 1/1, STD, T-type, liquids, order no. 7S11LEN00147, from Sartorius Stedim Biotech, as well as a differential pressure measuring device for the differential pressure between inlet and outlet of the filter housing. The filtered mass solution is determined. The measurement is terminated when the filtered mass flow has reached 5% of the maximum mass flow detected during the measurement. The filtered until this time mass solution is the measurement result life. The temperature of the solution is 20 ° C, the differential pressure between the inlet and filtratseitigem output of the filter housing is kept constant.

Definition of water flow of a filter element:

As the flow of that mass flow of water is defined, which flows through a filter element in a filter housing at a differential pressure of 0.5 bar between the inlet and filtratseitigem output.

Description of the measurement of water flow:

The measuring stand consists of a filter housing 1/1 STD T-Type Liquids Order No. 7S11LEN00147, from Sartorius Stedim Biotech. Furthermore, a differential pressure gauge for the pressure difference between the inlet and outlet of the filter housing and a flow meter for measuring the water flow rate is installed on the filter housing. The water temperature is 20 ° C. The flow is measured at a differential pressure set to 0.5 bar.

Example A (Figure 1):

There were two filter elements accordingly 1 prepared according to Ex. C, Ch. 10022583. The examinations and tests of the filter elements gave the following result: example / Heights fold ratio number of folds filter area tilt angle lifetime water flow Standardized service life Normalized water flow m ² ° kg l / min kg / m ² l / min m ² A 1: 1/20: 8 74:74 0.99 60 67 31.5 67 32 A1 1: 1/20: 8 74:74 0.99 60 42.6 36.9 43 37 Material list of filter elements Inner diameter (2 × R ₉ ) Backflow protection 3: 68 mm Outer diameter (2 × R ₁₀ ) Core 4: 32 mm Drainage material inside (Filtrate) novatexx 2035 Drainage material outside (Upstream): A: novatexx 2035 A1: extruded net prefilter: PESU, SSB Type 15445, Ch. 1050433 roll 107 Endfiltermaterial: PESU, SSB Type 15407, Ch. 1050313 roll 4

Example B (Figure 2):

There were filter elements accordingly 2 prepared according to Ex. C, Ch. 10002883 (1). The examinations and tests of the filter elements gave the following result: example / Heights fold ratio case number filter area tilt angle lifetime water flow Standardized service life Normalized water flow m ² ° kg l / min kg / m ² l / min m ² B 1: 1/16: 8 75:75 0.86 50 49.6 41.6 57 48 Material list of filter elements Inner diameter (2 × R ₉ ) Backflow protection 3: 68 mm Outer diameter (2 × R ₁₀ ) Core 4: 38 mm Drainage material inside (Filtrate) novatexx 2035 Drainage material outside (Upstream): novatexx 2035 prefilter: PESU, SSB Type 15445, Ch. 1050433 Endfiltermaterial: PESU, SSB Type 15407, Ch. 1050313

Example C (Figure 3):

There were filter elements accordingly 3 prepared according to Ex. C, Ch. 10002883 (1). The examinations and tests of the filter elements gave the following result: example / Heights fold ratio number of folds filter area tilt angle lifetime water flow Standardized service life Normalized water flow m ² ° kg l / min kg / m ² l / min m ² C 2: 1/16: 8 90:45 0.86 20 54.9 44.7 64 52 Material list of filter elements Inner diameter (2 x R ₉₎ Backflow protection 3: 68 mm Outer diameter (2 × R ₁₀ ) Core 4: 38 mm Drainage material inside (Filtrate) novatexx 2035 Drainage material outside (Upstream): novatexx 2035 prefilter: PESU, SSB Type 15445, Ch. 1050433 Endfiltermaterial: PESU, SSB Type 15407, Ch. 1050313

Example V1 (nonwoven):

There were filter elements accordingly 4 made according to the prior art according to Ex. C, Ch. 10027783. The examinations and tests of the filter elements gave the following result: example / Heights fold ratio number of folds filter area tilt angle lifetime water flow Standardized service life Normalized water flow m ² ° kg l / min kg / m ² l / min m ² V1 1.23 91 1 N / A 33.7 31.6 34 32 Material list of filter elements Inner diameter (2 × R ₉ ) Backflow protection 3: 68 mm Outer diameter (2 × R ₁₀ ) Core 4: 38 mm Drainage material inside (Filtrate) novatexx 2035 Drainage material outside (Upstream): novatexx 2035 prefilter: PESU, SSB Type 15445, Ch. 1050433 Endfiltermaterial: PESU, SSB Type 15407, Ch. 1050313

Example V2 (network):

There were filter elements accordingly 4 made according to the prior art according to Ex. C, Ch. 10027783. The examinations and tests of the filter elements gave the following result: example / Heights fold ratio number of folds filter area tilt angle lifetime water flow Standardized service life Normalized water flow m ² ° kg l / min kg / m ² l / min m ² V2 1.23 91 1.00 N / A 36.2 35.6 36 36 Material list of filter elements Inner diameter (2 × R ₉ ) Backflow protection 3: 68 mm Outer diameter (2 x R ₁₀₎ Core 4: 38 mm Drainage material inside (Filtrate) novatexx 2035 Drainage material outside (Upstream): extruded net prefilter: PESU, SSB Type 15445, Ch. 1050433 Endfiltermaterial: PESU, SSB Type 15407, Ch. 1050313

Comparable are:
Example A with V1,
Example A1 with V2 as well
Examples B and C with V1 and with A. Summary table: example / Heights fold ratio number of folds filter area tilt angle lifetime water flow Standardized service life Normalized water flow m ² ° kg L / min kg / m ² L / min m ² A 1: 1/20: 8 74:74 0.99 60 67 31.5 67 32 V1 1.23 91 1.00 N / A 33.7 31.6 34 32 A1 1: 1/20: 8 74:74 0.99 60 42.6 36.9 43 37 V2 1.23 91 1.00 N / A 36.2 35.6 36 36 B 1: 1/16: 8 75:75 0.86 50 49.6 41.6 57 48 C 2: 1/16: 8 90:45 0.86 20 54.9 44.7 64 52

In the comparison of Examples B and C with V1 or A shows that despite lower filter area in the examples (cause: outer diameter of the core is larger) due to the inventive pleating as in Example A a significant increase in the filtration performance over the prior art is achieved.

LIST OF REFERENCE NUMBERS

1

filter

2

filter element

3

backflow prevention

4

core

5

first fold

6

first fold height

7

second fold

8th

second fold height

9

Radius (backflow protection)

10

Radius (core)

11

Outer surface (core)

12

radial

13

tilt angle

14

The End

15

virtual radius

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 69329118 T2 [0005]
• DE 69334045 T2 [0005]
• DE 69333430 T2 [0005]
• DE 3935503 C2 [0008]

Claims (12)

Filter for filtering media with a pleated, cylindrical filter element ( 2 ), which is located between a perforated, cylindrical backflow preventer ( 3 ) and a broken, cylindrical core ( 4 ) is arranged, wherein the filter element ( 2 ) in pleated folds ( 5 . 7 ), wherein a plurality of folds ( 5 ) a first fold height ( 6 ) which is greater than the difference between the radius ( 9 ) of the backwater protection ( 3 ) and the radius ( 10 ) of the core ( 4 ) and the outer surface ( 11 ) of the core ( 4 ) directed away from a radial ( 12 ) by an angle of inclination ( 13 ) are inclined, characterized in that a plurality of folds ( 7 ) at least a second shorter fold height ( 8th ) and that the folds ( 7 ) of the second shorter fold height ( 8th ) of the backwater protection ( 3 ) radially adjacent and alternating the folds ( 5 ) of the first fold height ( 6 ) are arranged adjacent. Filter according to claim 1, characterized in that the number of folds ( 7 ) with a shorter fold height ( 8th ) is half as high or smaller as the number of wrinkles ( 5 ) with the first fold height ( 6 ). Filter according to claim 1, characterized in that the number of folds ( 7 ) with a shorter fold height ( 8th ) the number of folds ( 5 ) with the first fold height ( 6 ) corresponds. Filter according to one of claims 1 to 3, characterized in that the folds ( 7 ) of the shorter, second fold height ( 8th ) at its backwater protection ( 3 ) opposite end ( 14 ) on a virtual radius ( 15 ) that is greater than or equal to the radius ( 10 ) of the core ( 4 ) increased by one fourth of the difference between the radius ( 9 ) of the backwater protection ( 3 ) and the radius ( 10 ) of the core ( 4 ). Filter according to one of claims 1 to 4, characterized in that the folds ( 5 ) of the first fold height ( 6 ) at least in its not of wrinkles ( 7 ) a second fold height ( 8th ) adjacent area each have a tilt angle ( 13 ) of greater than 15 °. Filter according to claim 5, characterized in that the folds ( 5 ) of the first fold height ( 6 ) each have a tilt angle ( 13 ) of greater than 25 °. Filter according to claim 5 or 6, characterized in that the folds ( 5 ) of the first fold height ( 6 ) each have a tilt angle ( 13 ) of greater than 40 °. Filter according to one of claims 1 to 7, characterized in that the filter element ( 2 ) consists of successively arranged one or more layers of drainage or spacer material, one or more layers of filter material with a selective separation ability when flowing through and finally again one or more layers of drainage or spacer material. Filter according to claim 8, characterized in that the filter material of a polymeric porous membrane of polyethersulfone or polyamide or polyvinylidene fluoride or a cellulose derivative, such as cellulose mixed ester, cellulose acetate and / or cellulose nitrate, or cellulose or polypropylene or polyethylene or polytetrafluoroethylene and / or expanded polytetrafluoroethylene or polyvinyl chloride is trained. Filter according to claim 8, characterized in that the filter material of mineral or polymeric fiber filter media or bonded and / or unbound non-wovens, such as spunbonded or melt blown spunbonded or staple fiber webs or carded webs or cellulose or polyester or polyolefins, such as PE or PP, or glass fibers or micro glass fibers is formed. Filter according to claim 8, characterized in that the filter material is formed of a fabric or an extruded net of a polymer. Filter according to claim 8, characterized in that the filter material is formed of a functionalized porous filter medium, such as a modified polymer membrane of polyamide or polyethersulfone or cellulose acetate.

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